Hello all,

Just joined here, having found the site while searching for information relating to a presentation today at the National Audio Show about the Vertex AQ/Nordost/Quantum 'Measurement Initiative'. So I thought I'd post what I found to this thread....

The results shown look like nothing more than those one would expect due to time-slip between the device-under-test output and the sampling instant of the test instrument. I mean there's very little difference between them when the signal is nearly flat, and a lot when it changes rapidly. The phasing between signal and sampler is absolutely critical, but has zero effect in the real world of course, which is the biggest reason why this kind of test is usually avoided.

The 'Defence contractor' Advansys is a tiny outfit (turnover around £100,000 according to latest Companies House accounts) and a look at its website (Advansys Solutions - The New Contact in Sonar) suggests it doesn't actually work much on the signal-processing side of sonar anyway. Its 'audio subsidiary', Acuity Products Ltd, was set up in December last year and hasn't filed any accounts yet.

Only got into this because on the way home up the M6, I bet my mate a tenner that the claims would turn out to show nothing new - so far I look like winning, I guess!